The William T. Tibbals House, at 11 Old Middletown Road in the Cobalt section of the town of East Hampton, has an unusual shape that some have classified as an octagon but seems closer to an oval and is said to be known as “the round house.” The roof may have had an octagon shape at one time, but today it seems to have the sides of a dodecagon, or 12-sided polygon. The house was built in 1857, which was during the peak of the fad in construction of octagon houses, and it has the stucco exterior and bracketed roof typical of octagon house construction, so perhaps we could consider it a relative of the octagon houses. It was built for William Thadeus Tibbals, operated an oakum works (used for caulking wooden ships) on Cobalt Stream that had been started by his father, Thadeus Tibbals, in 1828. After William’s death, his widow lived in the house and his son, Irvin Tibbals, who continued the oakum business with William’s brothers.
